ESA project to create artificial space ecosystem A new European Space Agency (ESA) project is examining ways of using human waste to recreate an artificial ecosystem during space flights. The proposed system would provide oxygen and water and enable astronauts to grow their own food. The MELISSA project (Micro-ecological li... A new European Space Agency (ESA) project is examining ways of using human waste to recreate an artificial ecosystem during space flights. The proposed system would provide oxygen and water and enable astronauts to grow their own food. The MELISSA project (Micro-ecological life support alternative) aims to provide a workable system for long-haul space flights which may take years to complete and during which nothing will be thrown away - including human waste. The project goes further than other recycling systems used on Mir or the International space station, which purify water and recycle exhaled carbon dioxide, but do not attempt to recycle organic waste for food production. Christophe Lasseur, from the MELISSA project team at ESA's technical centre in the Netherlands, said: 'We are creating an artificial ecosystem which uses micro-organisms to process the waste so that we can grow plants.' The system uses five separate but interconnected compartments. In the first three sections, waste is progressively broken down using different fermentation processes. In the fourth compartment, algae or plants will grow to produce food, oxygen and water. The fifth compartment is where the 'consumers', or astronauts, would live. Lasseur compares the system to a lake: 'At the bottom is sludge (raw waste) which undergoes anaerobic (without oxygen) fermentation in darkness. Higher up there's light but no oxygen. Higher still there's oxygen and it's possible to transform ammonia to nitrate. At the surface, there's carbon dioxide, oxygen and light. This is where higher plants can thrive.' A small pilot plant is being built outside Barcelona, Spain, where a trial run will be carried out on three rats, which consume roughly the same amount of oxygen and carbon dioxide as a human being. It is hoped that the plant will be fully operational by 2005 with all five compartments working together. The next step will then be to build a larger plant for testing on humans. Ultimately, says Lasseur, the size of the plant will depend on what needs to be grown: 'You would need about 10 square metres growing area per person if you want to live on wheat, far less if you're happy with algae.' Those with a hunger for all things cosmic can find out more about man's exploration of space by visiting the ESA's new human spaceflight web service at the reference below. The site provides information under five main headings: Astronauts, the International space station, Research in space and The next step - education and the future. Visitors can use the site to access a wide range of information, from what life is like on a spacecraft to the possibility of finding other life forms.
